This invention relates generally to radar receiving apparatus and more particularly to a radar detector which is capable of simultaneously receiving and indicating detection of radar signals occurring within either of at least two frequency bands.
While the invention may find other utility, the description herein will be facilitated by reference to the detection of radar signals in the X- and K- bands. The United States Federal Communications Commission (FCC) has established that X-band radar signals be transmitted at 10.525 GHZ with a tolerance of .+-.0.025 GHZ, and that K-band radar signals be transmitted at 24.150 GHZ with a tolerance of .+-.0.100 GHZ. Many prior art receivers for these signals employ crystal detectors; however, these detectors frequently are not sufficiently sensitive to reliably detect radar signals over a long distance, and are subject to other deficiencies as well.
The prior art has also proposed the use of superheterodyne type receivers for the detection of such radar signals. However, the relatively broad FCC tolerances mentioned above have heretofore required, a relatively broad bandwidth for such reception.
Consequently, such receivers have exhibited frequency inaccuracies and drift, as well as limitations in sensitivity, signal-to-noise ration, and spurious signal rejection.